Shape and material optimization of building structures, including reducing the amount of concrete used, are very important aspects in sustainable construction. Numerical modelling is currently used very effectively to design optimized and sustainable structures, including their interaction with the surrounding rock environment. This paper is focused on the three selected factors of numerical modelling of fibre concrete slab and subsoil interaction: (1) the constitutive model of fibre concrete slab, (2) deformational and strength characteristics of subsoil, (3) effect of interface elements. The specialized geotechnical software Midas GTS NX, based on the finite element method, was used for the modelling of this task. Numerical results were compared with the experimental measurement of vertical displacements on the upper surface of slab. In the presented study, three constitutive models of slab recommended in MIDAS GTS NX code for modelling concrete behaviour (elastic, Mohr-Coulomb and Drucker-Prager) were applied. In addition, the sensitivity analysis with respect to the deformational and strength characteristics of subsoil was performed. The numerical study also presents the effect of the interface elements application on the slab behaviour. The numerical results of maximum vertical displacements based on the Drucker-Prager and elastic model underestimated both the experimental results and numerical results based on the Mohr-Coulomb model. From the qualitative point of view (shape of deflection curve), the numerical simulation showed the better agreement of the Mohr-Coulomb constitutive model with the experimental measurements in comparison with the other two investigated constitutive models. The performed parametric study documented that reduction of the strength and deformational characteristics of subsoil leads to the increase of maximum vertical displacements in the centre of slab, but the experimentally measured deflection curve, including uplift of slab and gapping occurrence between the slab and subsoil, was not achieved without the interface application.

中文翻译：

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纤维混凝土板与底土相互作用的数值模拟——选定决定因素的影响

建筑结构的形状和材料优化，包括减少混凝土的使用量，是可持续建筑中非常重要的方面。数值建模目前非常有效地用于设计优化和可持续的结构，包括它们与周围岩石环境的相互作用。本文重点研究了纤维混凝土板与地基相互作用数值模拟的三个选定因素：（1）纤维混凝土板的本构模型，（2）地基的变形和强度特性，（3）界面元素的影响。基于有限元方法的专业岩土工程软件 Midas GTS NX 被用于此任务的建模。数值结果与板坯上表面垂直位移的实验测量结果进行了比较。在本研究中，应用了 MIDAS GTS NX 代码中推荐的三种混凝土板本构模型，用于建模混凝土行为（弹性、Mohr-Coulomb 和 Drucker-Prager）。此外，还对地基的变形和强度特性进行了敏感性分析。数值研究还展示了界面元素应用对板坯行为的影响。基于 Drucker-Prager 和弹性模型的最大竖向位移数值结果低估了实验结果和基于 Mohr-Coulomb 模型的数值结果。从定性的角度（挠度曲线的形状），数值模拟表明，与其他两个研究的本构模型相比，Mohr-Coulomb 本构模型与实验测量的一致性更好。进行的参数研究表明，底土强度和变形特性的降低导致板中心最大垂直位移的增加，但实验测量的挠度曲线，包括板的隆起和板与底土之间的间隙出现，是没有接口应用程序无法实现。